Chapter 12 Organic Compounds with Oxygen and Sulfur 12.1 Alcohols, Thiols, and Ethers

Alcohols An alcohol contains a hydroxyl group (—OH) attached to a carbon chain. A phenol contains a hydroxyl group (—OH) attached to a benzene ring.

Naming Alcohols The names of alcohols in the IUPAC system replace the -e with -ol. with common names use the name of the alkyl group followed by alcohol. Formula IUPAC Common Name CH4 methane CH3─OH methanol methyl alcohol CH3─CH3 ethane CH3─CH2─OH ethanol ethyl alcohol

More Names of Alcohols IUPAC names for longer chains number the chain from the end nearest the -OH group. CH3─CH2─CH2─OH 1-propanol OH │ CH3─CH─CH2─CH3 2-butanol CH3 OH │ │ CH3─CH─CH2─CH2─CH─CH3 5-methyl-2-hexanol 6 5 4 3 2 1

Some Typical Alcohols | “Rubbing alcohol” CH3—CH—CH3 2-propanol (isopropyl alcohol) Antifreeze HO—CH2—CH2—OH 1,2-ethanediol (ethylene glycol) Glycerol HO—CH2—CH—CH2—OH 1,2,3-propanetriol

Learning Check Name the following compounds. 1. CH3—CH2—CH2—CH2—OH OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3.

Solution OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3-methyl-2-pentanol 1. CH3—CH2—CH2—CH2—OH 1-butanol OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3-methyl-2-pentanol 3. cyclopentanol

Phenols in Medicine Phenol is the IUPAC name for benzene with a hydroxyl group. is used in antiseptics and disinfectants. Phenol Resorcinol 4-hexylresorcinol Carbolic Acid

Derivatives of Phenol Compounds of phenol are the active ingredients in the essential oils of nutmeg, thyme, cloves, and vanilla. 9

Common Phenols/Alcohols 10

Common Phenols/Alcohols 11

Common Phenols 12

Herbicides produced by Phenols 13

Naming Phenols To name a phenol with two substituents, assign C-1 to the carbon attached to the –OH. number the ring to give the lowest numbers. 1 1 3 4 3-chlorophenol 4-bromophenol

Learning Check Write the structure of each of the following: A. 3-pentanol B. ethyl alcohol C. para-methylphenol

Solution Write the structure of each of the following: A. 3-pentanol OH | CH3—CH2—CH—CH2—CH3 B. ethyl alcohol CH3—CH2—OH C. para-methylphenol O H C 3

Thiols Thiols contain sulfur are similar to alcohols contain a thiol (-SH) group often have strong odors found in cheese, onions, garlic, and oysters are used to detect gas leaks

Thiols are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. (Methyl Mercaptan) 18 18 18

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Striped Skunk (Mephitis mephitis) Thiols E-2-buten-1-thiol 38-44% 3-methyl-1-butanethiol 18-26% 2-quinolinemethanethiol 3-12% 20

For pets that have been sprayed, bathe the animal in a mixture of 1 quart of 3% hydrogen peroxide (from drug store), 1/4 cup of baking soda (sodium bicarbonate) and a teaspoon of liquid detergent. After 5 minutes rinse the animal with water. Repeat if necessary. The mixture must be used after mixing and will not work if it is stored for any length of time. DO NOT STORE IN A CLOSED CONTAINER - it releases oxygen gas so it could break the container. This mixture may bleach the pet's hair. 21

Why tomato juice is believed to eliminate skunk odor Why tomato juice is believed to eliminate skunk odor. Bathing an animal in tomato juice seems to work because at high doses of skunk spray the human nose quits smelling the odor (olfactory fatigue). When this happens, the odor of tomato juice can easily be detected. A person suffering olfactory fatigue to skunk spray will swear that the skunk odor is gone and was neutralized by the tomato juice. Another person coming on the scene at this point will readily confirm that the skunk spray has not been neutralized by the tomato juice. 22

Quickly And Safely Eliminates Odors On Pets Thiotrol Spray is specially formulated to neutralize, not mask, offensive skunk odor on pets, people, clothing, carpets, and other contaminated surfaces. Directions Completely saturate affected areas with the high output pump sprayer. Work into fur, clothing, or carpet and allow to dry. Resaturate affected area and let dry. To avoid eyes, apply to face using a saturated cloth. Should any odors remain, locate odor source and reapply. Thiotrol Spray Caution For topical use only. Avoid contact with eyes. Sold Exclusively Through Veterinarians

Ethers An ether contains an ─O─ between two carbon groups. has a common name that gives the alkyl names of the attached groups, followed by ether. CH3─O─CH3 CH3─CH2─O─CH3 dimethyl ether ethyl methyl ether Propyl People Ether

Ethers as Anesthetics Anesthetics inhibit pain signals to the brain. like diethyl ether, CH3─CH2─O─CH2─CH3, were used for over a century, but caused nausea and were flammable. developed by the 1960s were nonflammable. Ethrane (enflurane) Penthrane 25

Chapter 12 Organic Compounds with Oxygen and Sulfur 12.2 Properties of Alcohols and Ethers 26 26

Boiling Points of Alcohols contain polar OH groups. form hydrogen bonds with other alcohol molecules. have higher boiling points than alkanes and ethers of similar mass. 27 27

Boiling Points of Ethers do not have a polar group. have an O atom, but there is no H attached. cannot form hydrogen bonds between ether molecules. 28 28

Solubility of Alcohols and Ethers in Water are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water. with 1-4 C atoms are soluble, but not with 5 or more C atoms. Copyright © 2009 by Pearson Education, Inc. 29 29

Comparing Boiling Points and Solubility Copyright © 2009 by Pearson Education, Inc. 30 30

Chapter 12 Organic Compounds with Oxygen and Sulfur 12.3 Reactions of Alcohols and Thiols 31 31

Combustion of Alcohols Alcohols undergo combustion with O2 to produce CO2 and H2O. CH3—CH2—OH + 3O2 2CO2 + 3H2O + Energy 32 32

Dehydration of Alcohols Alcohols undergo dehydration when heated with an acid catalyst. the loss of —H and —OH from adjacent carbon atoms. H OH | | H+, heat H—C—C—H H—C=C—H + H2O | | | | H H H H alcohol alkene 33 33

Learning Check Write the equations for the reaction of 2-propanol when it undergoes 1. combustion. 2. dehydration. 34 34

Solution OH │ CH3─CH─CH3 = 2-propanol = C3H8O 1. combustion 2C3H8O + 9O2 6CO2 + 8H2O 2. dehydration │ H+ CH3─CH─CH3 CH3─CH=CH2 + H2O 35 35

Oxidation and Reduction In an oxidation, there is an increase in the number of C-O bonds. there is a loss of H. In a reduction, there is a decrease in the number of C-O bonds. there is a gain of H. 36 36

Oxidation and Reduction 37 37

Oxidation of Ethanol in the Body enzymes in the liver oxidize ethanol. the aldehyde produced impairs coordination. blood alcohol over 0.4% can be fatal. Ethyl alcohol Acetaldehyde Acetic acid 38 38

Ethanol, CH3CH2OH Ethanol acts as a depressant. kills or disables more people than any other drug. is metabolized at a rate of 12-15 mg/dL per hour by a social drinker. is metabolized at a rate of 30 mg/dL per hour by an alcoholic. 39 39

Effect of Alcohol on the Body 40 40

Alcohol Contents in Common Products % Ethanol Product 50% Whiskey, rum, brandy 40% Flavoring extracts 15-25% ListerineTM, ScopeTM 20% Formula 44DTM 12% Wine, DristanTM 10% NyquilTM, CepacolTM 3-9% Beer, LavorisTM 41 41

Oxidation of Thiols When thiols undergo oxidation, an H atom is lost from each of two –SH groups. the product is a disulfide. [O] CH3─SH + HS─CH3 CH3─S─S─CH3 + H2O 42 42

Chapter 12 Organic Compounds with Oxygen and Sulfur 12.4 Aldehydes and Ketones 43

Carbonyl Group in Aldehydes and Ketones A carbonyl group in an aldehyde is attached to at least one H atom. in a ketone is attached to two carbon groups. 44

Naming Aldehydes An aldehyde has an IUPAC name in which the -e in the alkane name is changed to –al. has a common name for the first four aldehydes that use the prefixes: form (1C), acet (2C), propion (3C), and butyr (4C), followed by aldehyde. Methanal Ethanal Propanal (formaldehyde) (acetaldehyde) (propionaldehyde) 45

In a linear expression, the aldehyde group is often written as: CHO

In the linear expression of a ketone, the carbonyl group is written as: CO

Naming Aldehydes 48

Aldehydes in Flavorings Several naturally occurring aldehydes are used as flavorings for foods and fragrances. Benzaldehyde (almonds) Cinnamaldehyde (cinnamon) 49

Naming Ketones In naming ketones in the IUPAC system, the -e in the alkane name is replaced with –one. with a common name, the alkyl groups attached to the carbonyl group are named alphabetically, followed by ketone. Propanone 2-butanone (dimethyl ketone) (ethyl methyl ketone) 50

Ketones in Common Use Nail polish remover, solvent Propanone, dimethylketone, acetone Butter flavoring (Butanedione) 51

Aldehydes & Ketones in Nature 52

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Learning Check Name the following compounds: A. B. 2-pentanone; methyl propyl ketone 3,3-dimethylbutanal 58

Learning Check Draw the structural formulas for each: A. 4-methylpentanal B. 2,3-dichloropropanal C. 3-methyl-2-butanone 59

Chapter 12 Organic Compounds with Oxygen and Sulfur 12.5 Properties of Aldehydes and Ketones Hydrogen Bond Hydrogen Bond Acetaldehyde Acetone 60

Boiling Points + - + - + - Aldehydes and ketones have polar carbonyl groups (C=O). + - C=O attractions between polar groups. + - + - C=O C=O higher boiling points than alkanes and ethers of similar mass. lower boiling points than alcohols of similar mass. 61

Comparison of Boiling Points 62

Solubility in Water The electronegative O atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water. Hydrogen Bond Hydrogen Bond Acetaldehyde Acetone 63

Tollens’ Silver Mirror Test In Tollens’ test, Tollens’ reagent, which contains Ag+, oxidizes aldehydes, but not ketones. Ag+ is reduced to metallic Ag, which appears as a “mirror” in the test tube. Ag+ + e– → Ag(s) 64

Benedict’s Test In Benedict’s test, Benedict’s reagent, which contains Cu2+, reacts with aldehydes that have an adjacent OH group. an aldehyde is oxidized to a carboxylic acid, while Cu2+ is reduced to give brick red Cu2O(s). 65

green  orange  red  brown Increasing amounts of reducing sugar green  orange  red  brown 66